Portable internal combustion percussion tools



Oct. 28, 1958 R. w. GUTHRIE 2,857,888

PORTABLE INTERNAL COMBUSTION PERCUSSION TOOLS,

Filed May 17, 1957 I a Sheets-Sheet 1 Fig. 1

' INVENTOR. Haw/120M Game/E Has A 7' roeuev Oct. 28, 1958 R. wpGUTHRlE O 2,8

PORTABLE INTERNAL COMBUSTION PERCUSSION TOOLS Filed May 17,1957- s Sheets-Sheet 2 IN V EN TOR. E/cHA ED 14 urme/e H15 ArroeA/EY Oct. 28, 1958 R. w. GUTHRIE' 2,357,388

PORTABLE INTERNAL COMBUSTION PERCUSSION TOOLS Fil'ed May 17, 1957 l 3 Sheets-Sheet 5 INVENTOR. A E/CHAEDIMGUTH/Q/E BY l HlsA-rroelvsv Unite States Patent PORTABLE INTERNAL COMBUSTION PERCUSSION TOOLS Richard W. Guthrie, Indiana, Pa., assignor to Syntron Company, Homer City, Pa., a corporation of Delaware Application May 17, 1957, Serial No. 660,010 2 Claims. (Cl. 123-7) This invention relates generally to portable internal combustion percussion tools known as gasoline hammers, and more particularly to the control and operation of the working piston and the supplying of gas under pressure for automatically blowing out the hole being drilled during the operation of the hammer.

This invention is an improvement over assignees application Serial No. 565,660 filed February 15, 1956, and also over the invention as shown in the Bergman Patent 2,399,458.

Internal combustion percussion tools have different modes for controlling the timing piston which in turn controls the working piston. Some of these modes of control are by means of controlling the exhaust gases, or the application of a centrifugal brake or the applition of a hand brake, or the control through ignition. Each of these modes of control require some form of governor or specific application by the operator. Such a device becomes worn due to improper care and fails to function until it is cleaned or serviced. One of the principal objects of this invention is the provision of a new mode of control of operation of the working 2,857,888 Patented Oct. 28, 1958 ice Fig. 1 is a view in vertical section of the internal combustion percussion tool comprising this invention.

Fig. 2 is a view in side elevation of the structure shown in Fig. 1.

Fig. 3 is an enlarged sectional view showing the line for the combustion gases controlled by a manual valve together with those controlled and produced by the working piston.

Referring to Figs. 1 and 2, the internal combustion percussion tool comprises the cylinder 1 having attached to its upper end the crank case 2 which carries the bearings 3 that support the crankshaft 4. The upper end of the crankcase 2 is provided with a bracket 5 that has attached thereto the handle 6 and pivoted thereon is the fuel throttle control lever 7.

The cylinder 1 is provided with a combustion chamber 8 in which the engine piston 10 operates, the Wrist pin 11 to which the connecting rod 12 is attached. The other end is on the crank 13 of the crankshaft 4. In the other portion of the combustion chamber 8 is the working piston 14 which is made in two diameters, the upper or combustion piston part 15 and the lower or reaction piston part 16. This piston is provided with a downwardly projecting stem 17 the hardened steel end of which as indicated at 18 strikes the top 20 of the tool 21. The reaction piston 16 operates within the bounce chamber 22 which is divided into two parts, the upper or compression chamber 23 and the lower or reaction chamber 24.

The working piston 14 is provided with a hollow chamber 25 which acts as a portion of a compressor receiver that opens downwardly through the passage 27 to repiston without the use of such governors and by the direct manual control of exhaust gases to a receiving chamber where they are directed through the hollow tube to blow out the hole. The sudden release of the exhaust gases for this purpose provides apressure as high as seventy-five pounds per square inch which not chamber and thereby control the working piston.

Another object of this invention is the provision of an internal combustion percussion tool having a bounce chamber which is divided by the reaction piston into a reaction chamber and a compression chamber, the compression chamber of which supplies air under pressure to a receiving chamber for the purpose of blowing out the hole drilled by the tool during the operation of the piston and which is supplemented by the use of the manual control release of the discharged products of combustion for applying an increased supply of gas under pressure periodically to the receiving chamber for augmenting the blowing out of the hole.

Other objects and advantages appear hereinafter in the following description and claims.

The accompanying drawings show, for the purpose of exemplification without limiting the invention or claims thereto, certain practical embodiments illustrating the principles of the invention wherein:

ceiving chamber 28 at the striking end 18 of the working piston. The tool 21 also has passage 30 through which gases under pressure pass downwardly through the tool to where it opens into the bit, to blow the dust from the hole being drilled.

As shown in Fig. 2 this internal combustion percussion tool is provided with an outer casing 31 which encloses a carburetor, a gasoline tank 32 having a cap member 33 to supply fuel thereto. The fuel is carried from the tank 32 by means of the fuel line 34 to the carburetor 35 and thence it is supplied through a port 36 to the crankcase of the engine, and when the engine piston is drawn to its uppermost position this compressed and vaporized fuel is then allowed to pass to the combustion chamber where it is ignited by the spark plug 37 shown in Fig. 1 which is supplied with ignition from the magneto member 38 within the combustion fly wheel fan member 40 attached to one end of the crankshaft 4.

t The opposite end of the crankshaft 4 is provided with a starting pulley 41.

As shown in Fig. 2 the carburetor is provided with an inlet which is controlled by the hoke lever 42 actuated by the choke button 43 adjacent the top of the hammer.

The fuel control lever 7 is pivoted at 44 and is provided with a throttle 45 that actuates the lever member 46 which is pivoted at 47 and actuates the rod 48 that controls the supply of fuel through the carburetor throttle lever 50.

As shown in Fig. 1, the fan is provided with an opening 51 in the housing to admit the air which is blown around the cylinder to cool the same. It is also shown that the cylinder is provided with air cooled fins to aid in cooling.

As illustrated in Figs. 1 and 3 the cylinder combustion chamber 8 is provided with a port 53 which is connected to the passage 54 to the valve chamber 55, which is provided with a valve member 56 having a stem 57 that extends out of the chamber and is provided with a washer 58 locked thereon and which compresses the calibrated spring 60 against the seat and thus holds the valve member56 seated against the seat 61 to close the passage 54. When the pressure is sufirciently great to force ;the .valve openagain the pressure lin the reaction chamber-.124 and the pressureof the spring 60the-prod-' ucts .tof lcombustion are permitted to flowthrough the valve housing to the passage 62 to theunder side of' 'the reaction piston in the Ieactionchamber ZZ -of the bounce chamber- If. the gases are sufiic-iently strong to t raise the reaction-.pistonto the position as showntin Fig. 3, they are then permitted to escape through the gland members 63.to.the.chamber 28,2wheretthey are mixed'with the air .supplied thereto underrrpressure and :all ithesegases serve :topass down-through the. passage 30 --for--the purpose-of cleaning the hole that is being drilled;

The'valve chamber 55 is also provided with a passage 80 through. the tubing to the receiver chamber- 28. This passage is open to the passage 54 by means'of-the manually controlledslide valve 81 which is on the-end of the stem 82 that is connected bythe swivel connection 83 to the. actuating rod84. The-upper end-of the actuatingzrod 84 .is pivotally connectedto the end of the lever- 85 thatis mounted onthe-pivot 47 with the lever 46. The opposite end of the lever is'provided with an angle member 86- for engagement-by the hand to depress thesame andpull the slide valve 81 so as to open the passage 54 to the passage-8t) and-permit the products of combustion to flow directly to the receiver chamber 28. This-is done periodically and a pressure of approximately. seventy-five poundsiper square inch may be applied to .thechamber 28 by using the products of combustion to augment the pressure created by the compressor. The lever-85 is biased to close the sliding valve 81 .by means of the spring 87 which is connected to the back of member 88.

The reaction piston 16 is arranged to operate the compressor by closing .the port 64 which is also controlled bythe check valvedisofiS. Thus when the reaction piston is pushed downwardly by the products of combustion the compression chamber 23 draws air through the inlet '66 past'the valve 65 and through the port 64-into'the compression chamber 23. When'all of the air is drawninto this' compression chamber and the working piston is moved upwardly by its bounce reaction on its bounce or return stroke and may be aided by the pressure of the products of combustion through the valve 56. The airtrapped-in the compression chamber 23 is not.,permitted 'to:fiow' backout to the atmosphere by reason of the check valve" 65 r but is caused to flow through ther porti64; valve 71, passage 72 and the receiving-chambers: 25 :'and:28 'where it is. collected 'withthe products? of-tcombustionv discharged .through the glands 63 under pressure fromz th'e previous'explosion and passes on down through; the 'passa'ge 30 through the bitfor the purpose of blowing dust out of the hole being drilled. Thus the productsofcombustion,together with the compression ofaircreated bythe reaction piston in the compressionrchamber 23, function to provide a gas under pulsating pressure for the purpose of cont-inuously-blowing out the'hole.

ItwilI 'be noted that'whenrche:reaction'piston 16 'on its upward stroke closes the port 'fto the pas'sage"64=the entrapped space remaining in chamber 23 is the clearance space that-v produces a cushion. The iair is compressed in this space thuspreventing metalto m'etal contact :between the reaction pistonand .the housing.

The tool chuck 67 is provided with two seal member 68 which seals the hexagonally shaped tool member 21 and provides a ratchet member 70 which is actuated by the reciprocal movement of the working piston for the purpose of stepping the tool 21 in sequential steps to rotate the same while it is being reciprocated by the working piston.

The structure as shownin Fig. 3 illustrates in part a similar internal cornbus'ti'on'pe'rcussion tool wherein the port 53 connects with the passage 54 and is blocked by the pressure .biased 'checkva'lve 56. However, the gland members'63 are removed eliminating "any outlet to chamber 22 thereby. conserving energy stored in this chamber in the form of compressed gas.

The compressed air'passes out through the port 64 and the discharge valve 71 to the passageway 72 thence to the chamber 28. The check valve 71 permits the air to discharge from thepassageway 64 but prevents any return thereof. Thus :the products of combustion supplieddirectly to-the receiver chamber 28 by the line cannot escape back through the line 70. Thus the accumulative pressure from both sources of gases in the chamber 28 may reach as high as seventy-five pounds per square inch. This sudden high pressure at spaced intervals is'very effective in cleaning out the hole.

The passageway 64 also is provided withthe inlet check valve 65 which isopened to the atmospheric intake 66 as before. Thus the reaction piston 16 functions as a compressor.

I claim:

1. An internal combustion percussion tool comprising a housing containing a combustion chamber, a bounce chamber and a receiver, a timing captive piston and a free working piston in said combustion chamber, a reaction piston on the end of said working piston and reciprocable in said bounce chamber and providing therein acompressi'on chamber and a reaction chamber, a combustion gas passageway leading from the combustion chamberto a valve housing and thence branching to the bottom of said reaction chamber and to said receiver, a spring loaded check valve in said valve housing to control theflow -oLgases to said bounce chamber and a manually operated spring loaded valve to control the flow of gases to said receiver chamber.

2. An internal combustion percussion tool comprising a housing containing a combustion chamber, a bounce chamber and areceiver chamber, a timing captive piston and a working piston reciprocal in said combustion chamber, a reaction piston on the end of said working piston and reciprocable in said bounce chamber andpro vidingtherein a compression chamber and a reaction chamber, a tool bit in said receiving chamber having a blow out'passage, a passage valved by said reaction piston and forming an inlet and exhaust to said compression chamben-a check valved inlet connected to said passage,-a check valved outlet connecting to said passage to said receiver, a combustion gas passage leading from said combustionchamber to a valve housing and thence branching to the bottom of said reaction chamber and to said receiver, a spring loaded check valve in said valve housing to control the flow of gases to said bounce chamber, and a manuallytoperated spring biased control valve in said valve housing to control the flow of gases to said receiver chamber;

No references cited. 

